Chaeleg b



(No Model.)

0. B. BOSWORTH & F. A. SWAN. ARC LAMP GUT-OUT.

Fig-1,

UNITED, STATES PATENT OFFICE.

CHARLES R. BOSlVORTH AND FREDERICK A. SWAN, OF BOSTON, MASS.

ARC-LAMP CUT-OUT.

SPECIFICATION forming part of Letters Patent No. 278,679, dated June 5, 1883.

Application filed August 31, 1882. (No model.)

To a. whom it may concern: Be it known that we, CHARLES B. Boswonr and FEEDERIcK A. SWAN, both of Boston, in the county of Suffolk and State of Massachu setts, have invented certain new and useful Improvements in Short Circuit Bridges for Electric Lamps, 8m, of which the following is.

Our invention is illustrated in the following described drawings, in which Figure l is an elevation showing our device attached to an electric lamp; and Fig. 2 shows details in vertical section, the short circuit being closed.

A A B B represent the frame to which the lamp and its adjuncts are attached; D D, the illuminating electrodes; 0, the rod which serves to hold the upper electrode, D; and F H E E parts of an ordinary device for controlling the motion of the electrode D. As the above-named parts are not new, and their functions so well known, we will not further describe them.

The ordinary circuit for working the lamp passes through the line L, post I, wire L, magnet M, wire L magnets E E, wire L brush L*, rod 0, illuminatingelectrodes D D, cross-bar B, rod A, and 'post 1? to line L.

Our invention consists in inserting in the main line or circuit the electro-magnet M M and its connecting devices and wires, which may be described as follows: The coil M of the electro-magnet M M consists of a few convolutions of the main-circuit wire L L within the center of which the soft-iron core M, Figs.

- 1 and 2, is placed. At the lower end of the core M we attach a plug, M which should be of some good conducting metal. The bridge or short-circuit line starts from the post 1?, passes through the'wire N to the plate N, thence (when the core M is dropped, as shown in 2) through the plug M to the plate N wire N N, resistancecoil R, wire N and post P to line.

The operation of our invention is as follows: WVhen the current is passing through the lamp in its normal course the coil M, which is in the main circuit, suspends the core M, and thus holds the plug M" away from contact with the bridge-plates N N", as shown in Fig. 1; but if, from any cause whatever, the normal circuit is broken between the posts P and 1?,

then the coil M ceases to act, and the core M, with the plug lVP, will fall to the position shown 'in Fig. 2, in which case the short circuit on the line N N N N N* R N, is completed, and the lineoircuit restored outside of the lamp. The resistance-coil R is put in the bridge-line, so that in starting the current it may pass through the lamp-circuit, and in so doing eX- cite the electro-magnet M M, and thus with: draw the plug M, which action at once cuts the short circuit N N, 8nd, out, and leaves the wvhole force of the current to act on the lamp.

We claim In an electric light apparatus, the combination of the coil M (inserted in the normal circuit,) the core M, provided with the wedgeshaped plug M with the plates N N, and the wires N N all operating together substantially as described, and for the purpose set forth.

CHARLES B. BOSWORTH. FREDERICK A. SWVAN. \Vitnesses:

HELEN M. FEEGAN, WILLIAM EDSON. 

